You make some good points, but nowhere did I mean to advocate not planning ahead. I mean that the plan should focus on how the user is going to use the software. The plan should include how the features are going to complement one another, how closely they will be tied together, and whether they should be used at random times or in a fairly set sequence.

Once one understands how the input would be transformed into the output by a skilled and experienced member of the future end-user staff, one can design the interface around the process. The most important features are those that are used in every case, and the other features can be iterated in once there is a working and tested base of code that produces the default outputs.